ABSTRACT
Rapid advance of various technologies associated with unmanned aerial vehicles (UAVs) has enabled many complex tasks to be carried out with minimal human intervention. Even though obstacle sensing and an effective reactive collision avoidance guidance is an important feature and must be considered with due importance, one must not forget that the airframe of UAV reacts only to its control inputs in the form of fin deflections through altering its body rates. After pop-up obstacle detected in the close vicinity, the collision avoidance algorithm has two key components: to detect whether the obstacle can be a threat to the UAV and to steer it sufficiently in case the obstacle is a critical one. The ‘collision cone’ is an effective tool for detecting collision and finding an alternate direction of motion that will avert collision. While manoeuvring away from an obstacle by using aerodynamic control, it should be remembered that the vehicle thrust is also a control parameter.
